Java tutorial
/* * * Copyright (c) 2015 Caricah <info@caricah.com>. * * Caricah licenses this file to you under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. You may obtain a copy * of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software distributed under * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS * OF ANY KIND, either express or implied. See the License for the specific language * governing permissions and limitations under the License. * * * * */ package com.caricah.iotracah.server.mqttserver.transform; import com.caricah.iotracah.bootstrap.data.messages.*; import com.caricah.iotracah.bootstrap.data.messages.base.IOTMessage; import com.caricah.iotracah.server.transform.IOTMqttTransformer; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.handler.codec.mqtt.*; /** * @author <a href="mailto:bwire@caricah.com"> Peter Bwire </a> * @version 1.0 9/23/15 */ public class IOTMqttTransformerImpl implements IOTMqttTransformer<MqttMessage> { @Override public MqttMessage toServerMessage(IOTMessage internalMessage) { switch (internalMessage.getMessageType()) { case PublishMessage.MESSAGE_TYPE: PublishMessage pubMsg = (PublishMessage) internalMessage; //We generate a publish message. MqttPublishVariableHeader respVariableHeader = new MqttPublishVariableHeader(pubMsg.getTopic(), pubMsg.getMessageId()); MqttFixedHeader respFixedHeader = new MqttFixedHeader(MqttMessageType.PUBLISH, pubMsg.getIsDuplicate(), MqttQoS.valueOf(pubMsg.getQos()), pubMsg.getIsRetain(), 0); ByteBuf content = Unpooled.wrappedBuffer((byte[]) pubMsg.getPayload()); return MqttMessageFactory.newMessage(respFixedHeader, respVariableHeader, content); case AcknowledgeMessage.MESSAGE_TYPE: //Generate a PUBACK for qos 1 messages. AcknowledgeMessage ackMsg = (AcknowledgeMessage) internalMessage; MqttFixedHeader ackFixedHeader = new MqttFixedHeader(MqttMessageType.PUBACK, ackMsg.isDup(), MqttQoS.valueOf(ackMsg.getQos()), ackMsg.isRetain(), 0); MqttMessageIdVariableHeader msgIdVariableHeader = MqttMessageIdVariableHeader .from(ackMsg.getMessageId()); return MqttMessageFactory.newMessage(ackFixedHeader, msgIdVariableHeader, null); case PublishReceivedMessage.MESSAGE_TYPE: //We need to generate a PUBREC message to acknowledge reception of message. PublishReceivedMessage pubrec = (PublishReceivedMessage) internalMessage; MqttFixedHeader recFixedHeader = new MqttFixedHeader(MqttMessageType.PUBREC, false, MqttQoS.valueOf(pubrec.getQos()), false, 0); msgIdVariableHeader = MqttMessageIdVariableHeader.from(pubrec.getMessageId()); return MqttMessageFactory.newMessage(recFixedHeader, msgIdVariableHeader, null); case ReleaseMessage.MESSAGE_TYPE: //We need to generate a PUBREL message to release cached message. ReleaseMessage pubrel = (ReleaseMessage) internalMessage; MqttFixedHeader relFixedHeader = new MqttFixedHeader(MqttMessageType.PUBREL, pubrel.isDup(), MqttQoS.valueOf(pubrel.getQos()), false, 0); msgIdVariableHeader = MqttMessageIdVariableHeader.from(pubrel.getMessageId()); return MqttMessageFactory.newMessage(relFixedHeader, msgIdVariableHeader, null); case CompleteMessage.MESSAGE_TYPE: //We need to generate a PUBCOMP message to acknowledge finalization of transmission of qos 2 message. CompleteMessage destroyMessage = (CompleteMessage) internalMessage; MqttFixedHeader compFixedHeader = new MqttFixedHeader(MqttMessageType.PUBCOMP, false, MqttQoS.valueOf(destroyMessage.getQos()), false, 0); msgIdVariableHeader = MqttMessageIdVariableHeader.from(destroyMessage.getMessageId()); return MqttMessageFactory.newMessage(compFixedHeader, msgIdVariableHeader, null); case Ping.MESSAGE_TYPE: Ping ping = (Ping) internalMessage; //We need to generate a PINGRESP message to respond to a PINGREQ. recFixedHeader = new MqttFixedHeader(MqttMessageType.PINGRESP, ping.isDup(), MqttQoS.valueOf(ping.getQos()), ping.isRetain(), 0); return MqttMessageFactory.newMessage(recFixedHeader, null, null); case ConnectAcknowledgeMessage.MESSAGE_TYPE: ConnectAcknowledgeMessage connAck = (ConnectAcknowledgeMessage) internalMessage; MqttFixedHeader connAckFixedHeader = new MqttFixedHeader(MqttMessageType.CONNACK, connAck.isDup(), MqttQoS.valueOf(connAck.getQos()), connAck.isRetain(), 0); MqttConnAckVariableHeader conAckVariableHeader = new MqttConnAckVariableHeader(connAck.getReturnCode()); //Todo: Raise netty codec issue for lack of codec 3.2.2.2 Session Present flag. return MqttMessageFactory.newMessage(connAckFixedHeader, conAckVariableHeader, null); case SubscribeAcknowledgeMessage.MESSAGE_TYPE: SubscribeAcknowledgeMessage subAckMsg = (SubscribeAcknowledgeMessage) internalMessage; MqttSubAckPayload payload = new MqttSubAckPayload(subAckMsg.getGrantedQos()); MqttFixedHeader subAckFixedHeader = new MqttFixedHeader(MqttMessageType.SUBACK, subAckMsg.isDup(), MqttQoS.valueOf(subAckMsg.getQos()), subAckMsg.isRetain(), 0); MqttMessageIdVariableHeader subAckVariableHeader = MqttMessageIdVariableHeader .from(subAckMsg.getMessageId()); return MqttMessageFactory.newMessage(subAckFixedHeader, subAckVariableHeader, payload); case UnSubscribeAcknowledgeMessage.MESSAGE_TYPE: UnSubscribeAcknowledgeMessage unSubAckMsg = (UnSubscribeAcknowledgeMessage) internalMessage; respFixedHeader = new MqttFixedHeader(MqttMessageType.UNSUBACK, unSubAckMsg.isDup(), MqttQoS.valueOf(unSubAckMsg.getQos()), unSubAckMsg.isRetain(), 0); MqttMessageIdVariableHeader variableHeader = MqttMessageIdVariableHeader .from(unSubAckMsg.getMessageId()); return MqttMessageFactory.newMessage(respFixedHeader, variableHeader, null); default: /** * * Internally these are not expected to get here. * In such cases we just return a null * and log this anomaly as a gross error. * * * if(internalMessage instanceof ConnectMessage || * internalMessage instanceof SubscribeMessage || * internalMessage instanceof UnSubscribeMessage || * internalMessage instanceof DisconnectMessage || * internalMessage instanceof WillMessage ){ * } **/ return null; } } }